420 THE LIVER. 



the lime-pigment stones are not found very often in man, but often in 

 oxen. 



The pigment-stones are generally not large in man, but in oxen and 

 pigs they are sometimes found the size of a walnut or even larger. In 

 most cases they consist chiefly of calcium-bilirubin with little or no 

 biliverdin. Sometimes also small black or greenish-black, metallic- 

 looking stones are found, which consist chiefly of bilifuscin along with 

 biliverdin. Iron and copper seem to be regular constituents of pigment- 

 stones. Manganese and zinc have also been found in a few cases. The 

 pigment-stones are generally heavier than water. 



The cholesterin-stones, whose size, form, color, and structure may vary 

 greatly, are often lighter than water. The fractured surface is radiated, 

 crystalline, and frequently shows crystalline, concentric layers. The 

 cleavage fracture is waxy in appearance, and the fractured surface when 

 rubbed by the finger-nail also becomes like wax. By rubbing against 

 each other in the gall-bladder they often become faceted or take other 

 remarkable shapes. Their surface is sometimes nearly white and wax- 

 like, but generally their color is variable. They are sometimes smooth, 

 in other cases they are rough or uneven. The quantity of cholesterin 

 in the stones varies from 642 to 981 p. m. (RiTTER 1 ). The cholesterin- 

 stones sometimes contain variable amounts of lime-pigments, which may 

 give them a very changeable appearance. 



Cholesterin. The formula for this body, although not positively 

 determined, is generally given as C 2 7H 46 O (OBERMULLER) or C27H 44 O 

 (MAUTHNER and SUIDA). 



Because of the fact that from cholesterin, hydrocarbons which 

 have been called cholesteriline, cholesterone and cholesterilene, can be 

 prepared in different ways, it was believed that a certain analogy 

 exists between the cholesterin and the terpenes. The color reactions 

 as well as the recent investigations on the constitution of cholesterin 

 indicate that this body belongs to the terpenes. 



The constitution of cholesterin has not been completely determined, 

 although we have the very laborious and thorough investigations, of 

 many workers of whom we especially mention MAUTHNER and SUIDA, 

 WINDAUS, STEIN, DIELS and ABDERHALDEN. 2 From these investigations 

 we conclude that cholesterin is a monoatomic, unsaturated, secondary 

 alcohol whose hydroxyl group exists in a hydrogenized ring, indeed 

 between two methyl groups, and which also contains an isopropyl group. 

 It is also generally admitted that cholesterin contains only one double 



1 Journ. de 1'anat. et de la physiol. (Robin), 1872. 



2 The literature on cholesterin can be found in Windaus, Arch. d. Pharm., 246, 

 Hft. 2, and especially in Glikin, Bioch. Centralbl., 7, 372-377. 



